干旱区自然资源地表基质细化分类体系构建与调查深度 postprint

Abstract: The classification of the ground substrate is a fundamental basis for conducting ground substrate surveys and monitoring. It reveals the synergistic coupling relationship between the ground substrate and the surface cover layer, which aids in understanding the mechanisms of interaction between the ground substrate and the ecological environment from both the surface cover and subsurface spatial elements. This study targeted the Sangong River Basin in Xinjiang, a typical inland river basin in an arid region. Based on the heterogenous distribution of the mountain-oasis-desert landscape in arid regions, a three-tier classification and zoning system for ground substrates was developed, considering the distribution area, elevation range, and main surface cover of the surface substrates. The overall classification was divided into four primary categories, 17 secondary categories, and 28 tertiary categories. Considering the physical and chemical properties of the soil and the distribution characteristics of vegetation root systems, the suitable survey depth for ground substrates in the southern mountainous area was 50 cm; in the central plain area, it was 3 m; and in the northern desert area, it was less than 10 m. Additionally, based on the differentiation characteristics of Net Primary Productivity in vertical zonal ecosystems, the rationality of the classification system was validated, reflecting the role of ground substrate layers in nurturing and supporting land cover. These results provide theoretical and technical support for future natural resource surveys, monitoring, and scientific management decisions in arid regions.